Joseph



(No Model.)

J. W. THOMPSON. v

STEAM ENGINE GOVERNOR. No. 310,479. Patente(11121.11. 6, 1885.

FIG.2.

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NITED- STATES PATENT OFFICE.

JOSEPH \V. THOMPSON, OF SALEM, OHIO, ASSIGNOR OF ONEHALF TO THE BUCKEYEENGINE COMPANY, OF SAME PLACE.

STEAM-ENGINE GOVERNOR.

SPECIFICATION forming part of Letters Patent No. 310,479, dated January6, 1885.

Application filed August 15, 1884.

To all whom it may concern.-

Be it known that I, J osnrn W. Tnonrson, of Salem, in the'county ofGolumbiana and State of Ohio, have invented certain new and usefulImprovements in Steam-Engine Governors, of which improvements thefollowing is a specification.

My invention relates to centrifugal governors'of the class in which theposition of a valve operating eccentric relatively to the crank-line isvaried by the movements of weights rotating with the crank-shaft undervarying degrees of centrifugal force, to the end of effecting regulationof the speed of the engine by variations in the travel of the valve, andconsequently in the period of steamedmission, in accordance withvariations in pressure or resistance, an instance of which'class isexemplified in Reissued Letters Patent No. 8,433, granted and issued tomyself and the Buckeye Engine Company, as my assignee, under date ofSeptember 24, 1878.

The object of my invention is to provide a governor of such character ofsimple and inexpensive construction and ready application in which areembodied the features of an increased range of traverse of the weights,effective application of the centripetal action of the springs, capacityof adjustment of relative static and dynamic friction, and convenientadaptability to operation in either direction of rotation of thecrankshaft.

The improvements claimed are hereinafter fully set forth.

In the accompanying drawings, Figure l is a face view of a governorembodying my invention, and Fig. '2 a transverse section through thesame at the line w x of Fig. 1.

In therpractice of my invention the mechanism of the governor issupported on and carried by a wheel or disk, 1, which may either be thefly-wheel of the engine or a wheel separately secured upon thecrank-shaft. The eccentric 2, by which movement is imparted to the valvegoverning the admission and exhaust of steam to and from the cylinder ofthe engine, is formed with or secured to an arm, 3, which is pivoted tothe wheel 1 in proper angular relation to the crank by a journal, 41,secured to the arm 3, and mounted in a bearing, 28, on the wheel, theeccentric surround- (No model.)

ing the shaft and having suificient space in the internal openingthrough which the shaft pivot, the mean direction of the eccentric-rodbeing parallel wit-h the center line of the en gine,

is either in accordance radially with or directly 6o opposite radiallyto the crank, the latter being proper when the valve admits steam by itsmovement from the end at which admission is to be effected in the mannerof the ordinary slide-valve, audits direction of movement relatively tothe eccentric is not reversed by intermediate gean. Under suchconditions, and where the travel of the valve equals that of theeccentric, the distance from the center of the eccentric to the centerof its pivot equals the distance from the center of the pivot to thecenter of the shaft, less the combined lap and lead of the valve. If thearm 3 be so located that the center line of the eccentric is in linewiththe axes of the crank-shaft and of its pivot, the 7 5 movement of thevalve will be coincident with but in opposite direction from that of thepiston, and will be only of sufficient extent to uncover the steam-portat the induction for the amount determined as the mini- 8o mum lead,which should not be suflicient to run the unloaded engine up to speed.Movement of the eccentric-arm from this position in either directionwill increase the radius of eccentricity and consequently the travel ofS 5 the valve, change the angular position of the eccentric, and eil'ectmovement of the engine in a direction contrary to that of the advance ofthe eccentric. As a result of the increase of movement and of thebackward change of angular position of the eccentric the cut-off iseffected later in the stroke, while the lead is but slightly changed,the measure of such change being the departure of the segmental path ofthe center of the eccentric due to its pivotal movement from a straightline at right angles to the crank, and consequently the change of leadwill be inversely proportional to the length of the eccentric-arm. Thechange of lead being to increase with later degrees of cut-off isdesirable in compensating for the diminished compression attendingdelayed cut-off, and, further, for the reason that increase of travelnecessitates a proportionately increased absolute amount to approximaterelative equality. V

The adjustments of the eccentric 2 toward and from the angular positionabovespecified to wit, with its center in line with the axes of theshaft and of its pivot 4t-are effected by the action of pivoted weights5 under induced centrifugal force and of centripetally-acting springs 6,respectively. The weights 5 are secured upon the outer ends ofweight-arms \7 8, which are pivoted to the wheel 1 at diametricallyopposite points in a line perpendicular to the crank, and on oppositesides of said line, by pins or bolts 9, and the weight arms 7 8 arecoupled to the eccentric 2 by links 10, one of which is attached to theweight arm 7 between the pivot and the weight thereof, and the other toan arm, 11, projecting inwardly from the weight-arm 8, beyond its pivot,the weightarms 7 8 thus being levers of the second and of the first order, respectively, and, by their outward movements under the influenceof centrifugal force, acting conjointly to move the eccentric to wardthe center of the shaft.

Under the above construction I am enabled to materially enlarge therange of movement of the weight-arms relatively to correspondingmechanism heretofore employed, and thereby to attain close regulationwith, the employment of centripetally-aeting springs of correspondinglyreduced initial tension. The traverse of each weight-arm is arrested atthe proper inward and outward limits by two stop-pins, 12, formed of orfaced with wood or other suitable yielding material, which are fitted insockets 13 14 on the supportingwh eel 1; and to admit of the adjustmentof the parts for an opposite direction of rotation of the crank-shafttwo supplemental stop-pin sockets, 15 16, are provided for eachweight-arm, the sockets 13 14 and 15 16 being located symmetrically oneach side of the line join ing the centers of the weight-arm pivots.Centripetal force in opposition to the outward movements of the weights5 is exerted by a two plate-springs, (i, secured at one end to a block,18, pivoted to the wheel 1 adjacent to its periphery, said springsextending inwardly therefrom, and hearing at their opposite ends againsta roller, 19, journaled on a pin, 20, on the eccentric, and a roller,21, on a pin, 22, in the wheel 1, adjacent to its hub. The sides of theblock 18, which carries the springs (5, are of such taper as to impartto the springs a divergence which will cause them to be straight whennot under tension, and by the pivotal connection of the block the twosprings receive and impart strain equally. The construction furtheradmits of the springs being removed, slightly set, and reversed, iffound not to be sufficiently elastic, so that subsequent flexure may beimparted in an opposite direction. The roller 21 is adjustable towardand from the radial line connecting the centers of the shaft and of thespring-block pivot, in order to vary the tension of the springs, by aset-screw, 23, engaging a thread in the arm of the wheel which carriesthe pivot 22 of the roller, and bearing at its inner end on said pivot,which passes through a hole which is slotted or elongated in line withthe setscrew 23. The pivot 22 is held firmly in adjusted position by anut and washer. A supplemental socket, 24, having a similarly-slottedhole, and located on the opposite side of the radius connecting theshaft and springblock centers, serves to receive the pivot 22 when theparts are adjusted for a reverse direction of rotation of the shaft. Thereversal is effected by changing the relative position of the weightarmsand turning their opposite sides outward, so that, as in the adjustmentfirst described, their pivot ends lead and their weight ends follow inthe rotation of the shaft, and as each weightarm works on the same sideof the line joining the pivotcenters, as before, it will be seen thatthe supplemental sockets 15 16 are properly located to receive thestop-pins. The roller 21 is also similarly adjustable in thesupplemental socket 24. The gravity of the eccentric 2 is balanced by acounter-weight, 25, on an arm. 26, fixed on the eccentric-pivot 4t andprojecting through an opening, 27, in the bearing 28 thereof, which isoutwardly inclined or tapered to admit of the traverse of the armresultant on the adjustments of the eccentric. It has been found inpractice that the best results are obtained when the effective amount ofthe counter-weight is somewhat less than that required for a completegravity-bat ance, for the following reason:

In governors of this class, in which a valve opposing a certain amountof resistance is to be actuated, a certain degree of friction isdesirable of that character which opposes adj ustment in eitherdirection, and which may be termed static friction, in eontradistinctionto the friction of the actuated parts,which, tending to produce a changeof adjustment in particular direction, may be called dynamic friction.The static friction is in 'proper degree when it is just sufficient toprevent the dynamic resistance from sensibly disturbing the equilibriumof the governor, yet not suiiicient to prevent such minute degree ofdisturbance as will, by frequently overcoming the static friction in aslight degree, cause its action to be as sensitive to minute changes ofload and pressure as though the parts were without friction. Thecounter-weight 25, in addition to acting as a gravity-balance, alsoexerts centrifu al force, which augments the static friction of theeccentric-pivot 4 in its bearing, and in some cases such augmentation offriction may be sufiicient to make it in excess, and thereby to producesluggishness of action. In such case, if the effectiveness of thecounter-weight be diminished, which is provided for by mounting itadjustably and removably upon its arm 26 and securing it thereto by aset-screw, 29, so that it may be shifted inwardly or be removed andreplaced by a lighter counter-weight, the friction induced by itscentrifugal force will be reduced, and the correspondingly unbalancedweight of the eccentric will cause an equivalent increase in the dynamictendencies, so that by the adjustment of the weight upon the arm a pointmay be reached at which the static and dynamic tendencies will be insuch relation one to the other as to enable the greatest prac ticabledegree of sensitiveness consistent with suliicient stability ofequilibrium to be attained. Such adjustment will vary for differentspeeds, so that to enable the engine to be properly regulated for anydesired speed the adjustability ofthe counter-weight becomes ofsubstantial value and importance.

I claim as my invention and desiretosccure by Letters Patent 1. In asteam-engine governor, the combination, substantially as set forth, of asupporting wheel or disk, a valve-operating eccentric pivoted thereto,two weighted arms pivoted to the supporting-wheel at points in a lineperpendicular to the line joining the centers of said wheel and ot' theeccentricpivot, and adapted to move about their pivots on opposite sidesof the line joining the same, links coupling the eccentric with theweightarn'is, and connected to the latter on opposite sides,respectively, of their pivots, and apair of plate'springs connected atone end to the supportingwheel at a pointsub stantially in line with thecenters of said wheel and of the eccent ic-pivot, and abut-ting at theother against stops on the wheel and on the eccentric, respectively.

2. In a steam-engine governor, the combination, substantially as setforth, of a supporting wheel or disk, a valve-operating eccentricpivoted thereto, weighted arms pivoted to said wheel and adapted to berelatively reversed in position thereon, links connecting said arms withthe eccentric, stop-pin sockets located in pairs 011 opposite sides or adiametric line connecting the weight-arm pivots, a pair of stop-pins foreach weight arm, adapted to fit in the sockets on either side of saidline,a spring-stop adapted to fit in either of two sockets adjacent tothe eccentric, and on opposite sides of a line perpendicular to the linejoining the weight-arm pivots, and springs connected to thesupporting'wheel and bearing against said stop and against a stop on theeccentric.

3. In a steam-engine governor, the combi nation, substantially as setforth, of a supporting wheel or disk, a valve-operating eccentricpivoted thereto, weighted arms pivoted to said wheel and coupled to theeccentric, a spring-block pivoted to the supportingwheel, and having itssides tapered or in clined toward the periphery thereof, and a pair ofplate-springs secured to the sides of the springblock, and adapted tobear against stops on the supporting-wheel and the eccentric,respectively.

4. In a steam-engine governor, the combination, substantially as setforth, of a supporting wheel or disk, a valve-operating eccentricpivoted thereto, a counter-weight connected adj ustably to saideccentric, and weights and springs acting to vary the position of saideccentric by the exertion of centrifugal and centripetal force,respectively, thereon.

In a steam-engine governor, the combination,' substantially as setforth, of a sup porting wheel or disk, a valve-operating eccentricpivoted thereto, weighted arms pivoted to the supportingwheel andcoupled to the eccentric, an adjustable spring-stop connected to saidwheel, and springs secured at one end to said wheel and bearing at theother against said adj ustable stop and against a stop on the eccentric.

6. In a steam-engine governor, the combination, substantially as setforth, of a spring block having inclined or tapered sides and an openingfor a pivot by which it may be secured to the supporting wheel or caseof the governor, and a pair of flat plate springs con nected to thesides of the springblock, these members being combined for jointoperation to admit of the reversal and setting of the springs.

JOSEPH XV. THOMPSON. \Vitnesses:

PETER AMBLER, ALBERT CAMERON.

